The planting of corn, soybeans, and other crops is typically performed by driving a tractor through the field pulling a toolbar implement. The toolbar implement consists of a frame supported by wheels or tracks and having a transverse bar to which multiple planting units are attached. The planting units are spaced apart along the transverse bar to correspond to the seed rows that will be planted. The term “toolbar” is used interchangeably in the industry to refer to the implement as a whole and to the transverse bar specifically. As used herein, the term “toolbar” refers specifically to the transverse bar to which the planting units are attached and the term “toolbar implement” refers to the implement as a whole.
Toolbar implements are also used in other farming operations. For example, multi-functional row units are often attached to the toolbar implement to simultaneously till (also known as cultivate or plow), plant, and fertilize in one pass through the field. This method of farming is known as strip tillage, zone tillage, or strip till farming. As used herein, the term “row unit” refers to any type of planter, tiller, fertilizer, multi-functional unit, or the like that is attached to a toolbar implement.
Toolbar implements commonly contain toolbars that have widths of 20 feet (which can accommodate 8 planting units spaced thirty inches apart), 30 feet (which can accommodate 12 planting units spaced thirty inches apart), and more. The toolbars are so wide that they commonly are hinged so that the overall width of the implement can be reduced for storage and to travel upon public roads.
FIGS. 1 and 2 illustrate a typical wheeled toolbar implement. The implement contains a main longitudinal frame having a connector at the front and a hitch at the rear. The toolbar is divided into three sections, a hinged left wing, a fixed center, and a hinged right wing. In FIG. 1, the two wings are shown extended (the working position). In FIG. 2, the two wings are shown folded forward against the main frame (the storage and transport position). Spaced apart on the center toolbar are four wheel assemblies. Each wheel assembly contains a bracket, a motion dampener, a lift arm, and a wheel. The lift arms are hydraulic cylinders controlled by the tractor operator that can raise the frame for storage or transport. Row units are attached to the center toolbar in the spaces between the wheel assemblies.
While toolbar implements containing wheels are more common, toolbar implements containing track assemblies are becoming more popular. Track assemblies make contact with the ground with larger surface areas (footprints) and therefore reduce soil compaction and improve the ability to operate in wet fields. A toolbar implement with track assemblies is disclosed in Houck, U.S. Pat. Appln. Publn. No. 2006/0090910, May 4, 2006. The Houck implement has left and right wing toolbars that are located aft of (behind) and above the track assemblies. A track assembly for a toolbar implement is described in Rosenboom, U.S. Pat. No. 7,726,749, issued Jun. 1, 2010, incorporated by reference.
Many farmers would like to convert their wheeled toolbar implements to tracks. Unfortunately, tracks take up so much more space that interference problems usually arise. As a result, track assemblies generally cannot simply be substituted for wheels.
Accordingly, there is a demand for an improved method for converting a wheeled toolbar implement to a tracked toolbar implement. There is also a demand for an improved toolbar implement having tracks instead of wheels.